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<a name="boost.proto.transforms_type"></a><div class="titlepage"></div>
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<h2><span class="refentrytitle">Struct transforms_type</span></h2>
<p>boost::proto::transforms_type — 
          The type used to define the global <code class="computeroutput"><a class="link" href="transforms.html" title="Global transforms">proto::transforms</a></code>,
          a key for use when creating and accessing a slot in a transform environment for
          a set of external transforms.
        </p>
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<h2 class="refsynopsisdiv-title">Synopsis</h2>
<div class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../proto/reference.html#header.boost.proto.transform.when_hpp" title="Header &lt;boost/proto/transform/when.hpp&gt;">boost/proto/transform/when.hpp</a>&gt;

</span>
<span class="keyword">struct</span> <a class="link" href="transforms_type.html" title="Struct transforms_type">transforms_type</a> <span class="special">{</span>

  <span class="comment">// <a class="link" href="transforms_type.html#id-1_3_32_5_52_2_1_1_3-bb">public member functions</a></span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Value<span class="special">&gt;</span> 
    <a class="link" href="env.html" title="Struct template env">env</a><span class="special">&lt;</span><span class="identifier">transforms_type</span><span class="special">,</span> <em class="replaceable"><code><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span></code></em><span class="special">&gt;</span> <a class="link" href="transforms_type.html#id-1_3_32_5_52_2_1_1_3_1_1-bb"><span class="keyword">operator</span><span class="special">=</span></a><span class="special">(</span><span class="identifier">Value</span> <span class="special">&amp;</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Value<span class="special">&gt;</span> 
    <a class="link" href="env.html" title="Struct template env">env</a><span class="special">&lt;</span><span class="identifier">transforms_type</span><span class="special">,</span> <em class="replaceable"><code><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span></code></em><span class="special">&gt;</span> <a class="link" href="transforms_type.html#id-1_3_32_5_52_2_1_1_3_1_2-bb"><span class="keyword">operator</span><span class="special">=</span></a><span class="special">(</span><span class="identifier">Value</span> <span class="keyword">const</span> <span class="special">&amp;</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.32.5.54.4.4"></a><h2>Description</h2>
<p>
            The <code class="computeroutput">proto::transforms_type</code> type, along with the <code class="computeroutput"><a class="link" href="transforms.html" title="Global transforms">proto::transforms</a></code>
            global, are declared using the <code class="computeroutput"><a class="link" href="../../BOOST_PROTO_DEFINE_ENV_VAR.html" title="Macro BOOST_PROTO_DEFINE_ENV_VAR">BOOST_PROTO_DEFINE_ENV_VAR</a>()</code> macro.
          </p>
<div class="refsect2">
<a name="id-1.3.32.5.54.4.4.3"></a><h3>
<a name="id-1_3_32_5_52_2_1_1_3-bb"></a><code class="computeroutput">transforms_type</code> public member functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
<pre class="literallayout"><a name="id-1_3_32_5_52_2_1_1_3_1-bb"></a><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Value<span class="special">&gt;</span> 
  <a class="link" href="env.html" title="Struct template env">env</a><span class="special">&lt;</span><span class="identifier">transforms_type</span><span class="special">,</span> <em class="replaceable"><code><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span></code></em><span class="special">&gt;</span> <a name="id-1_3_32_5_52_2_1_1_3_1_1-bb"></a><span class="keyword">operator</span><span class="special">=</span><span class="special">(</span><span class="identifier">Value</span> <span class="special">&amp;</span> value<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Value<span class="special">&gt;</span> 
  <a class="link" href="env.html" title="Struct template env">env</a><span class="special">&lt;</span><span class="identifier">transforms_type</span><span class="special">,</span> <em class="replaceable"><code><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span></code></em><span class="special">&gt;</span> <a name="id-1_3_32_5_52_2_1_1_3_1_2-bb"></a><span class="keyword">operator</span><span class="special">=</span><span class="special">(</span><span class="identifier">Value</span> <span class="keyword">const</span> <span class="special">&amp;</span> value<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>
                If <code class="computeroutput">Value</code> is a specialization <code class="computeroutput">boost::reference_wrapper&lt;T&gt;</code>,
                this function returns <code class="computeroutput"><a class="link" href="env.html" title="Struct template env">env</a>&lt;transforms_type, T &amp;&gt;(value.get())</code>.
              </p>
<p>
                Else, if the type <code class="computeroutput">Value</code> is non-copyable (i.e., a function, an array, abstract, or an ostream),
                this function returns <code class="computeroutput"><a class="link" href="env.html" title="Struct template env">env</a>&lt;transforms_type, Value <em class="replaceable"><code>cv</code></em> &amp;&gt;(value)</code>,
                where <code class="computeroutput"><em class="replaceable"><code>cv</code></em></code> is <code class="computeroutput">const</code> for the second overload, and empty
                for the first.
              </p>
<p>
                Otherwise, this function returns <code class="computeroutput"><a class="link" href="env.html" title="Struct template env">env</a>&lt;transforms_type, Value&gt;(value)</code>.
              </p>
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<div class="copyright-footer">Copyright © 2008 Eric Niebler<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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